U.S. patent application number 13/510102 was filed with the patent office on 2012-09-13 for contactless coupling and method for use with an electrical appliance.
Invention is credited to Michael Rodway, Johnny Fabian Russell, Christopher Scott Trewin, Christian Albin Weimann.
Application Number | 20120228529 13/510102 |
Document ID | / |
Family ID | 43991089 |
Filed Date | 2012-09-13 |
United States Patent
Application |
20120228529 |
Kind Code |
A1 |
Trewin; Christopher Scott ;
et al. |
September 13, 2012 |
CONTACTLESS COUPLING AND METHOD FOR USE WITH AN ELECTRICAL
APPLIANCE
Abstract
The present invention relates to a coupling and various methods
of use of the coupling. In one embodiment the invention provides a
coupling for use with an appliance operated by a power supply,
which coupling allows mounting/dismounting of the appliance without
electrical isolation from the supply said coupling comprising: a) a
mounting member having a first encapsulated transformer element and
suitable controls connectable to the power supply, said member
being suitable for fixing to a structure; and b) a holder member
engageable with said mounting member, wherein the holder member is
suitable for holding or for connecting thereto an appliance, said
holder member having other suitable controls and a second
encapsulated transformer element able conduct power to an
appliance; c) wherein engagement of the first and second members is
able i) to cause induction of current in the second encapsulated
transformer element enabling powering of an appliance and ii) is
able to cause a signal to be carried between the controls and an
appliance to control and/or monitor the appliance; and wherein
disengagement of the first and second members results in no
induction and no carriage of the signal.
Inventors: |
Trewin; Christopher Scott;
(Wynyard, AU) ; Russell; Johnny Fabian; (Battery
Point, AU) ; Weimann; Christian Albin; (Mountain
River, AU) ; Rodway; Michael; (Lower Snug,
AU) |
Family ID: |
43991089 |
Appl. No.: |
13/510102 |
Filed: |
November 12, 2010 |
PCT Filed: |
November 12, 2010 |
PCT NO: |
PCT/AU2010/001513 |
371 Date: |
May 16, 2012 |
Current U.S.
Class: |
250/551 ; 29/876;
315/70 |
Current CPC
Class: |
F21V 25/12 20130101;
F21W 2131/101 20130101; F21V 25/02 20130101; F21W 2131/103
20130101; F21V 23/02 20130101; H02J 50/10 20160201; Y10T 29/49208
20150115; H02J 5/005 20130101; F21Y 2115/10 20160801; H05B 47/21
20200101; F21W 2131/402 20130101; F21S 8/086 20130101; F21V 21/116
20130101; H01F 38/14 20130101 |
Class at
Publication: |
250/551 ; 315/70;
29/876 |
International
Class: |
G02B 27/62 20060101
G02B027/62; H01F 38/14 20060101 H01F038/14; H01J 7/44 20060101
H01J007/44 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 16, 2009 |
AU |
2009905570 |
Claims
1-29. (canceled)
30. A coupling for use with an appliance operated by a power
supply, which coupling allows mounting/dismounting of the appliance
without electrical isolation from the supply said coupling
comprising: a) a mounting member having a first encapsulated
transformer element and suitable controls connectable to the power
supply, said mounting member being suitable for fixing to a
structure; and b) a holder member engageable with said mounting
member, wherein the holder member is suitable for holding or for
connecting thereto an appliance, said holder member having other
suitable controls and a second encapsulated transformer element
able conduct power to an appliance; c) wherein engagement of the
mounting member and the holder member is able i) to cause induction
of current in the second encapsulated transformer element enabling
powering of an appliance and ii) is able to cause a signal to be
carried between the controls and an appliance to control and/or
monitor the appliance; and wherein disengagement of the mounting
member and the holder member results in no induction and no
carriage of the signal.
31. The coupling of claim 30 wherein said controls allows the
appliance to operate in a range of power supply voltages and/or
detect the presence or absence of the appliance on the
coupling.
32. The coupling of claim 30 wherein the signal is carried by a
communications path between said controls of the first encapsulated
transformer element and said other controls of the second
encapsulated transformer element wherein the communications path is
an optical path comprising infrared light.
33. The coupling of claim 32 wherein the optical path is a light
tube.
34. The coupling of claim 33 wherein communication is provided by
an IR LED and an IR receiver.
35. The coupling of claim 30 wherein the appliance is selected from
the group comprising a lamp fitting, instrumentation, electrical
motor, process control/instrumentation devices, flow control valve,
electricity meter, smart meter, submeters and status indicators
including proximity switches, pressure switches, flow indicators,
valves, pH meters and the like.
36. The coupling of claim 30 wherein the appliance is a lamp
fitting comprising LED.
37. The coupling claim 30 wherein the members are configured so as
to i) ensure alignment of the communication path when the members
are engaged and ii) form a protective housing having a longitudinal
axis, wherein outer surfaces of the encapsulated elements are
physically contactable through 360.degree. of rotation about the
axis.
38. The coupling of claim 30 suitable for use with an industrial or
commercial lamp fitting and wherein, when engaged, the members form
a weather resistant housing.
39. An integrated lamp fitting and holder member suitable for
coupling with a mounting member having a first encapsulated
transformer element and suitable controls connectable to the power
supply, said member being suitable for fixing to a structure.
40. Use of the coupling of claim 30 to mount an appliance to a
structure.
41. A method of manufacture of coupling for use with an appliance
operated by a power supply, which coupling allows
mounting/dismounting of the appliance without electrical isolation
from the supply said method comprising producing a coupling: by
assembling a) a mounting member comprising a first encapsulated
transformer element and suitable controls connectable to the power
supply, said mounting member being suitable for fixing to a
structure; and by assembling b) a holder member engageable with
said mounting member, wherein the holder member is suitable for
holding or for connecting thereto an appliance, said holder member
having other suitable controls and a second encapsulated
transformer element able conduct power to an appliance; c) wherein
engagement of the mounting member and the holder member is able i)
to cause induction of current in the second encapsulated
transformer element enabling powering of an appliance and ii) is
able to cause a signal to be carried between the controls and an
appliance to control and/or monitor the appliance; and wherein
disengagement of the mounting member and the holder member results
in no induction and no carriage of the signal.
42. An improved method of mounting an appliance operated by a power
supply, which method allows mounting/dismounting of the appliance
without electrical isolation from the supply said method
comprising: providing a) a mounting member having a first
encapsulated transformer element and suitable controls connectable
to the power supply, said member being suitable for fixing to a
structure; and engageable with said mounting member, b) a holder
member suitable for holding or for connecting thereto an appliance
said member having a second encapsulated transformer element and
other suitable controls able conduct power to the appliance; c)
wherein engagement of the mounting member and holder member is able
i) to cause induction of current in the second encapsulated
transformer element enabling powering of an appliance and ii) is
able to cause a signal to be carried between the controls and an
appliance to control and/or monitor the appliance; and wherein
disengagement of the mounting member and holder member results in
no induction and no carriage of the signal; and fixing said
mounting member to a structure, connecting it to the power supply,
engaging the holder member and associated appliance with the
mounting member.
43. An improved method of maintenance of lamp fittings or other
appliances operated by a power supply which method allows
mounting/dismounting of the fittings or other appliances without
electrical isolation from the supply said method comprising:
provision of lamp fittings or other appliances associated with
couplings each coupling comprising a) a mounting member having a
first encapsulated transformer element and suitable controls
connectable to the power supply, said mounting member being
suitable for fixing to a structure; and b) a holder member
engageable with said mounting member, wherein the holder member is
suitable for holding or for connecting thereto an appliance, said
holder member having other suitable controls and a second
encapsulated transformer element able conduct power to an
appliance; c) wherein engagement of the mounting member and the
holder member is able i) to cause induction of current in the
second encapsulated transformer element enabling powering of an
appliance and ii) is able to cause a signal to be carried between
the controls and an appliance to control and/or monitor the
appliance; and wherein disengagement of the mounting member and the
holder member results in no induction and no carriage of the signal
the improvement comprising that replacement of lamp fittings or
other appliances can be carried out under full power load by
disengaging said the holder member and replacing it with a fresh
lamp fitting or other appliance attached to a second holder member
directly, or via a cable.
44. The coupling of claim 30 wherein the encapsulated transformer
elements comprise windings in the form of suitable printed or
etched material.
45. A method of providing proximity activated control of
luminescence in at least one lamp comprising providing: a lamp
fitting operated by a power supply and mounted on a structure in a
location, wherein the lamp is associated with a coupling which
allows mounting/dismounting of the lamp without electrical
isolation from the supply, the coupling comprising a) a mounting
member mounted on a structure having a first encapsulated
transformer element and suitable controls connected to the power
supply; b) a holder member engageable with said mounting member,
wherein the holder member holds or has connected thereto a lamp,
said holder member having other suitable controls and a second
encapsulated transformer element able conduct power to the lamp; c)
where one of the members includes a wireless digital radio
transceiver able to receive signals from and transmit signals to
said coupling attached to the structure within range and receive
signals from and transmit signals to a control station; d) wherein
engagement of the mounting member and the holder member causes i)
induction of current in the second encapsulated transformer element
to power the lamp; and ii) is able to cause a signal to be carried
between the controls and lamp to control and/or monitor the lamp;
and wherein disengagement of the mounting member and the holder
member results in no induction and no carriage of the signal; and
e) wherein luminescence of the lamp is controlled by a remote
controller via the radio transceiver said remote controller being
operational within a predetermined distance from the coupling
and/or manually.
46. The method of claim 45 wherein the remote controller is carried
by a person or vehicle.
47. A method of providing a distributed supervision control and
data acquisition network for controlling appliances remotely
comprising providing: lamp fittings or other appliances operated by
a power supply and mounted on power poles or other structures in a
location and wherein the appliances are associated with couplings
which allow mounting/dismounting of the appliances without
electrical isolation from the supply, each coupling comprising a) a
mounting member mounted on a power pole or other structure having a
first encapsulated transformer element and suitable controls
connected to the power supply; b) a holder member engageable with
said mounting member, wherein the holder member holds or has
connected thereto the appliance, said holder member having other
suitable controls and a second encapsulated transformer element
able conduct power to the appliance; c) where one of the members
includes a wireless digital radio transceiver able to receive
signals from and transmit signals to couplings attached to other
poles or structures within range and receive signals from and
transmit signals to a control station; d) wherein engagement of the
mounting member and the holder member causes i) induction of
current in the second encapsulated transformer element to power the
appliance; and ii) is able to cause a signal to be carried between
the controls and the appliance to control and/or monitor the
appliance; and wherein disengagement of the mounting member and the
holder member results in no induction; and e) wherein the coupling
is able to receive signals from and transmit signals to the control
station allowing remote control of the appliance in b) or another
appliance associated with the network.
48. A method of operating and controlling an appliance by
inductively coupling the appliance to a power supply via a coupling
which coupling allows mounting/dismounting of the appliance without
electrical isolation from the supply said method comprising
providing a coupling comprising: a) a mounting member having a
first encapsulated transformer element and suitable control
circuitry connected to the power supply; and b) a holder member
engageable with said mounting member, wherein the holder member
holds or has connected thereto an appliance, said holder member
having suitable control circuitry and a second encapsulated
transformer element able conduct power to the appliance; c) wherein
engagement of the mounting member and the holder member i) causes
induction of current in the second encapsulated transformer element
thereby powering the appliance and ii) causes a signal to be
carried between the control circuitry and the appliance to control
and/or monitor the appliance; and wherein disengagement of the
mounting member and the holder member results in no induction and
no carriage of the signal.
49. The coupling of claim 30 wherein the controls and other
controls comprise appropriately programmed CPU.
50. An industrial, non domestic coupling for use with an
industrial, non domestic appliance operated by a power supply,
which coupling allows safe and intrinsically safe
mounting/dismounting of the appliance without electrical isolation
from the supply said coupling comprising: a) a mounting member
having a first encapsulated transformer element and suitable
controls connectable to the power supply, said member being
suitable for fixing to a structure; and b) a holder member
engageable with said mounting member, wherein the holder member is
suitable for holding or for connecting thereto an industrial, non
domestic appliance, said holder member having other suitable
controls and a second encapsulated transformer element able conduct
power to an appliance; c) wherein said members are securable
together and of suitable configuration and strength to support the
appliance; d) wherein engagement of the mounting member and the
holder member is able: i) to cause induction of current in the
second encapsulated transformer element enabling powering of the
other controls; ii) to indicate the presence an appliance engaged
with the second transformer element by a signal being carried
between said controls and to allow powering of an appliance; iii)
to cause a signal to be carried between the controls and an
appliance to control and/or monitor the appliance and wherein
disengagement of the mounting member and the holder member results
in the absence of communication between said controls and results
in said first encapsulated transformer element going into a power
off condition.
51. The coupling of claim 50 wherein the signal is carried by a
communications path between the mounting member and the holder
member and the members are configured so as to ensure alignment of
the path when the members are engaged.
Description
TECHNICAL FIELD
[0001] The present invention relates to a coupling for use with
electrical appliances such as lamp fittings particularly those
present at industrial sites where hazardous conditions or exposed
conditions exist. These are environments containing gases, fumes,
dust and fluids and include mining sites, factories, roads and road
tunnels and the like.
BACKGROUND ART
[0002] Electric lamp fittings and other powered appliances are in
common use across the world in both domestic and
industrial/commercial situations.
[0003] Industrial lamp fittings and other powered appliances used
in industrial situations such as instrumentation, electric motors,
control valves, junction boxes and process instrumentation and the
like may be large and heavy and mounted inconveniently for
maintenance because of being mounted at height or present in a
dangerous environment. Such lamps and other appliances may be
mounted to a spigot at the end of a pole or on a proprietary
bracket.
[0004] Due to conditions present at various industrial sites
maintenance of lamps and other electrical appliances often presents
difficulties. For example, control valves, junction boxes and
process instrumentation need to be removed for maintenance,
inspection or repair as in situ operations are either onerous for
the worker or not allowed due to safety considerations. Similarly
in the case of light fittings, the light fitting needs to be
removed from the mounting or disassembled, maintenance work carried
out and the light fitting reassembled, if necessary and then
secured back to the mounting in one operation. As specialized
lifting equipment is generally required to gain access to such
lights and other appliances, these maintenance operations are
carried out by the maintenance personnel on an elevated work
platform, scissor lift, scaffold or other apparatus, which presents
difficulties and may be expensive due to hourly hire rates
applicable to such equipment. Similar difficulties arise in any
situation in which work is carried out on location rather than in a
workshop environment, for example, lights mounted on elevated
walkways and other elevated points for example in mine sites.
Further difficulties include interference with traffic or any other
operations being conducted in the vicinity of the light fitting.
For example whilst working at height the area has to be barricaded
and traffic and personnel restrictions are put in place. Access
equipment is charged out by the hour making most simple tasks such
as changing a light globe expensive.
[0005] In addition to the above difficulties hazardous areas
present an even greater challenge. Hazardous areas are classified
as such due to the presence of gas, vapours, solvents, chemicals,
dust, and any other combustible material being present in the work
or plant environment. The restrictions placed upon workers carrying
out maintenance in these areas are extremely high. At no point can
a worker have live or powered terminals exposed to the atmosphere
containing these combustible materials. Gas testing and monitoring
must be carried out before and during any maintenance can commence.
Basically to carry out any maintenance the worker must be able to
completely isolate all power from the equipment being tested and
worked on or have a mechanism that allows the equipment to be
removed from the power supply prior to being dismantled and worked
on.
[0006] All electrical equipment in hazardous areas must have
periodic detailed inspections carried out on them (by law) As these
are detailed inspections requiring all components of the equipment
to be inspected, all power must be removed from the equipment so
this may be carried out.
[0007] The time taken to carry out these inspections is substantial
and extremely costly as the electricians must be specially trained
to carry out these checks and maintenance.
[0008] The type of light fittings used in hazardous areas are big,
bulky fittings. Added to this cost is the high maintenance aspect
of the fittings.
[0009] Further, in order to constrain carbon emissions, control of
electrically powered appliances is desirable. This may be in an
attempt to decrease power consumption and/or to take into account
varying power availability at certain times. As electricity
generation becomes more decentralized and more power is derived
from renewable sources the need to control such an appliance
becomes more apparent at all levels: industrial, civic and
private.
[0010] The present inventors developed an interest in inductively
powering apparatus to attempt to address at least some of these
issues.
[0011] A number of proposals have been put forward to power
appliances in the lighting field and other fields including a
family of related inventions by inventor Baarman and others such as
US 20030201731, US 200030214255, US 20030214257, US 20040164686, US
2006 0284713, US 20070085487 and US 20100072826. The Baarman
inventions concern inductively coupled power to devices mainly in
the field of UV sterilization of water. US 20070085487, for example
primarily relates to a ballast circuit but mentions an inductive
coupling and refers to optical control of the shorting device for
start up of the UV lamp.
[0012] WO 2001 016995 by inventor Haynes discloses a split
transformer in which the secondary is attached to an illuminable
item such as a drinks coaster or poker chip and the primary side is
present on a table. The power supply is continuous and when the
coaster or poker chip is placed on the table it lights up.
[0013] WO 2003 009653 by inventors Bucks and Nijhof relates to a
power supply arrangement driving for a LED aimed at reducing EMI
interference by a particular switching regime.
[0014] EP E0478306 Kakitani discloses an apparatus for providing
stable DC power for a control circuit to operate a discharge lamp
with a primary and secondary inductive winding.
[0015] DE202004014497U1 by inventor Yen discloses an inductively
powered LED lamp for use in a water filled vessel with primary and
secondary windings.
[0016] Other proposals using varied appliances have also been put
forward. For example CN201535441 relates to a battery powered
"intrinsically safe work lamp", CN 201083345 discloses inductively
rechargeable battery powered torch and CN 201263620 relates to an
inductively powered lamp on a cordless kettle.
[0017] While particular proposals relating to lighting such as by
inventors Limpkin and Rozenberg have been put forward, there are
doubts about whether these would be practical for operating the
appliance. For example WO2004/097866 appears to disclose a two part
induction coupling linking an AC winding on a half core of a split
transformer to a secondary winding connected to a load such as a
lamp.
[0018] Yet other disclosures such as U.S. Pat. No. 6,188,179 by
inventor Boys relate to a transformer for use with fluorescent
lights in environments where arcing is undesirable. In this system
a primary coil may be run around the cabin of a boat, for example
and when light is required a fluorescent lamp attached to a
C-shaped coil, acting as the secondary winding is hooked over the
primary coil. The primary coil carries current in the order of 60A
requiring specialized fit out. While arguably this allows the
connection/disconnection of the lamp without danger it does not
provide a system which would be easily adapted to everyday use in
homes, offices or industrial sites.
[0019] In a completely different field Japan Patent Application
2000-252145 by inventor Kuki Heiji discloses a two part induction
connector in which there is optical communication between the
primary and secondary sides. The connector is designed to be
permanently incorporated in the door or of a van and allows
powering of the windscreen wiper and indicator light upon opening
and closing of the van door.
[0020] The above references to and descriptions of prior proposals
or products are not intended to be, and are not to be construed as,
statements or admissions of common general knowledge in the
art.
[0021] The present invention attempts to overcome at least in part
the aforementioned difficulties associated with operating,
controlling and maintaining electrical appliances including
industrial lamp fittings.
DISCLOSURE OF THE INVENTION
[0022] In one aspect the present invention provides a coupling for
use with an appliance operated by a power supply, which coupling
allows mounting/dismounting of the appliance without electrical
isolation from the supply said coupling comprising:
[0023] a) a mounting member having a first encapsulated transformer
element and suitable controls connectable to the power supply, said
member being suitable for fixing to a structure; and b) a holder
member engageable with said mounting member, wherein the holder
member is suitable for holding or for connecting thereto an
appliance, said holder member having other suitable controls and a
second encapsulated transformer element able conduct power to an
appliance; c) wherein engagement of the first and second members is
able i) to cause induction of current in the second encapsulated
transformer element enabling powering of an appliance and ii) is
able to cause a signal to be carried between the controls and an
appliance to control and/or monitor the appliance; and wherein
disengagement of the first and second members results in no
induction and no carriage of the signal.
[0024] power direct from the power source in order to operate and
includes lamp fittings, instrumentation, electrical motors, process
control/instrumentation devices, flow control valves, modems,
electricity meters, smart meters and submeters such as the Shark
100-S.TM. from Electro Industries/GaugeTech and status indicators
i.e. proximity switches, pressure switches, flow indicators,
valves, pH meters and the like.
[0025] The term "a power supply" refers to an electrical power
supply or source such as a mains supply, generator supply, or
photovoltaic supply of electricity and includes an extra low
voltage (ELV) supply. The term also includes a combined power
and/or signal overlay such as a high frequency control signal.
[0026] The term "mounting and dismounting without electrical
isolation" refers to the fact that the circuit on which the
appliance is wired does not have to be disconnected or switched off
to The term "appliance" refers to refers to any piece of electrical
equipment which consumes protect a worker when placing the fitting,
replacing the fitting or otherwise handling or carrying out
maintenance on the fitting. The invention allows for easy,
convenient mounting/dismounting of the appliance.
[0027] The term "mounting member" refers to a component of suitable
form and strength to support the appliance such as a lamp
fitting.
[0028] The transformer elements are part of a transformer. A
transformer is an appliance for transferring electrical energy from
one electrical circuit to another. While in the traditional
transformer it is desirable for the elements to be in physical
contact in the present invention the transfer of energy occurs
without direct electrical contact between the transformer elements
themselves. Thus while the mounting and holder members come into
physical contact upon engagement with each other, the transformer
elements do not come into physical contact with one another but
nonetheless are in close physical proximity sufficient to allow
induction of current. The circuit windings are insulated with
lacquer or other insulating material.
[0029] The term "first encapsulated transformer element" refers to
the primary winding of the transformer connectable to the power
supply and comprises a coil of conductive material. This may be in
the form of copper wire. Alternatively, printed material such as
multilayer printed circuit board (PCB) coils may be used.
[0030] The term "encapsulated" refers to the transformer element
being encapsulated or sealed within an appropriate medium such as a
suitable non-conductive resin, polymer or plastic.
[0031] Similarly the term "second . . . transformer element" refers
to the secondary side winding of the transformer and comprises a
coil of conductive material. The second encapsulated transformer
element is connectable to and able to power the appliance.
[0032] The terms "suitable controls" and "other suitable controls"
refer to circuitry or other means which are able to control or
regulate the light fitting or other appliance. For example the
control circuitry may operate to regulate the supply of power and
/or control operation of the lamp or other appliance. The control
circuitry may transmit to and/or receive signals, communications or
data from the first and second members or components thereof.
Suitable control circuitry may include central processing units
(CPU) and associated circuitry. Preferably the CPU and associated
circuitry enable the appliance to work in a range of power supplies
such as a range of 110 to 240V.
[0033] The term "connectable to the power supply" refers to the
first encapsulated transformer element having the appropriate
fittings to be wired to the power supply when the coupling is
installed for use.
[0034] The term "suitable for fixing to" in relation to the
mounting member means that it is suitable to be mounted on, secured
to, or fixed to a structure, such as the spigot mounting on a lamp
post or directly to a wall or building.
[0035] The term "structure" refers to any structure or support on
which an appliance such as a lamp fitting may be mounted such as a
spigot in the case of lighting at mining sites, street lamp posts
and includes other structures such as a larger piece of equipment
of which the appliance forms a part and, also includes planar
structures as on buildings or walls, or a purpose built
bracket.
[0036] The term "a holder member engageable with said mounting
member" means that these members are suitable for joining together
or otherwise engaging with each other. Preferably the holder member
is fixable or securable to the mounting member.
[0037] The term "suitable for holding, or connecting thereto, an
appliance" means that the member is configured so as to hold or
support the appliance such as a lamp fitting, or is configured so
as to enable a connection to be made, via a cable or the like,
between said lamp fitting or other appliance and the power
supply.
[0038] Similarly the term "able to conduct power to an appliance "
in relation to the second encapsulated transformer element means
that the element has the appropriate fittings to allow current to
flow to the lamp or other appliance when induction of current
occurs between the two elements.
[0039] The term "engagement of the first and second members is able
to cause induction of current in the second encapsulated
transformer element enabling powering of the appliance " means
that, when engaged, the first and second members are configured
such that current is able to pass from the first transformer
element to the second transformer element without direct electrical
contact between the elements.
[0040] The term "is able to cause a signal to be carried between
the controls and an appliance" means that engagement of the two
members enables carriage, conveyance and or transmission of a
signal between the control circuitry and the appliance. A signal
includes a control signal, a command or instruction issued from a
controller to the lamp fitting or other appliance. This can be by
direct means such as by a signal which travels along the power
supply to the appliance via the coupling in the form of an
appropriate voltage or high frequency overlay issued by a control
device such as a programmable logic controller (PLC) or a data
control system (DCS) to appliance connected to the holder member.
The signal may also be provided by other non-contact means such as
optical transmission or radio frequency (RF) including WiFi.
[0041] The term "between" refers to one way or bidirectional travel
of signals. Preferably the coupling of the present invention is
able to convey a reply signal from the appliance back to the
control device indicating that the device is operational or that
the control signal has been received. Thus in a preferred form of
the invention the coupling may operate as a conduit for operational
communications and feedback between an appliance and a control
centre. Preferably the control signal is an optical signal, more
preferably an infrared (IR) signal.
[0042] The term "to control and/or monitor the appliance" means to
cause the appliance or a factor relating to the operation of the
appliance such as current to be controlled or modulated. Monitoring
includes sensing the presence/absence of the appliance and its
functioning.
[0043] The term "disengagement" in relation to the members refers
to disengagement sufficient to stop current flowing between the
transformer elements and/or sufficient to stop the signal passing
between the transformer elements. Preferably disengagement of the
members results in loss of a feedback loop signal from the second
member and allows for sensing of presence of absence of the
appliance via sensing engagement/disengagement of the second
member. Depending on the type of signal used transduction may cease
before signal transmission as the members are progressively pulled
apart.
[0044] An advantage of the coupling of the present invention is
that it is contactless and therefore there is no opportunity for
arcing on disconnection or reconnection. In addition the invention
provides for easy connection/disconnection of the appliance from
the power supply. Thus the coupling allows safe disconnection under
full power load.
[0045] The encapsulated transformer elements may be provided by a
suitable configuration. Preferably the encapsulated transformer
elements are provided by a first core and having a primary winding
and a second core having a secondary winding, where the cores are
disposed face to face when the coupling is engaged. The windings
may be toroidal in configuration. Alternatively the encapsulated
transformer elements may be provided by a male component made of a
core and having a primary winding and a female component having a
secondary side winding, where the female component present in the
member sits over the male component. Alternatively, the arrangement
may be reversed with the primary winding in the female component
and the secondary side winding in the male component.
[0046] Preferably the signal of the coupling of the present
invention is carried by a communications path between controls of
the first encapsulated transformer element and the other controls
of the second encapsulated transformer element. Preferably a
communications path is provided between the face to face annular
cores and the members are configured so to align the path when
engaged. Preferably the path comprises an axis perpendicular to the
faces of the cores and runs through the centres of the cores. Even
more preferably the there is a feedback loop between the two
elements allowing compensation for variable induction efficiency
which may be caused by varying mechanical tolerances when the first
and second members are manufactured and/or engaged/disengaged
during use.
[0047] Preferably the communications path is provided by an optical
(including non-visible light) means. The optical means preferably
involves use of light in the infrared range. Preferably the light
passes through a light pipe or light tube. This provides a low cost
and reliable means of signaling.
[0048] Preferably the coupling of the present invention is suitable
for use with any electrical appliance but particularly lamp or
light fittings. The term "lamp fitting" refers to an appliance
which contains a lamp such as an incandescent, fluorescent, light
emitting diode (LED) or other type of lamp and a lamp holder and
also includes luminaires. The term may also include control
equipment such as the ballast, the reflector, the diffuser and
other components making up the fitting. More preferably the
coupling is suitable for use with industrial and/ or commercial
lamp fittings.
[0049] The term "industrial and/or commercial" refers to lamp
fittings which are non-domestic in nature and are generally
specialized bulky and/or heavy lamp fittings used in workplace,
commercial and public settings generally as opposed to domestic or
home-based situations. It encompasses mining sites, roadways,
tunnels, parking lots including multi-storey parking lots,
buildings such as factories, sporting facilities and venues other
settings where industrial or commercial scale lighting is required.
More preferably the coupling is used with lamp fittings comprising
LEDs wherein the current in the second encapsulated transformer
elements is set between minimum and maximum parameters suitable for
the particular LEDs.
[0050] A further advantage of the present invention is that the
coupling is non-arcing and can be used safely in environments where
hazardous conditions exist such as explosive dusts and gases in
mining, petrochemical industries, food factories and bakeries where
flour or other dried ingredients may form explosive dust clouds and
wet environments even in fully submerged environments such as
swimming pools. The coupling may be also used with lighting at
sites where inclement weather or other conditions make lighting
maintenance difficult. A particular advantage of the present
invention is that it avoids the need for compliance with costly and
complicated procedures in electrical maintenance such as isolation
of circuits when working in combustible or otherwise hazardous
environments.
[0051] In another aspect the invention provides a method of
manufacture of coupling for use with an appliance operated by a
power supply, which coupling allows mounting/dismounting of the
appliance without electrical isolation from the supply said method
comprising producing a coupling: [0052] by assembling a) a mounting
member comprising a first encapsulated transformer element and
suitable controls connectable to the power supply, said member
being suitable for fixing to a structure; [0053] and by assembling
b) a holder member engageable with said mounting member, wherein
the holder member is suitable for holding or for connecting thereto
an appliance, said holder member having other suitable controls and
a second encapsulated transformer element able conduct power to an
appliance; c) wherein engagement of the first and second members is
able i) to cause induction of current in the second encapsulated
transformer element enabling powering of an appliance and ii) is
able to cause a signal to be carried between the controls and an
appliance to control and/or monitor the appliance; and wherein
disengagement of the first and second members results in no
induction and no carriage of the signal.
[0054] In another aspect the present invention provides a method of
operating and controlling an appliance by inductively coupling the
appliance to a power supply via a coupling which coupling allows
mounting/dismounting of the appliance without electrical isolation
from the supply said method comprising providing a coupling
comprising: [0055] a) a mounting member having a first encapsulated
transformer element and suitable control circuitry connected to the
power supply; and b) a holder member engageable with said mounting
member, wherein the holder member holds or has connected thereto an
appliance, said holder member having suitable control circuitry and
a second encapsulated transformer element able conduct power to the
appliance; c) wherein engagement of the first and second members i)
to causes induction of current in the second encapsulated
transformer element thereby powering the appliance and ii) causes a
signal to be carried between the control circuitry and the
appliance to control and/or monitor the appliance; and wherein
disengagement of the first and second members results in no
induction and no carriage of the signal.
[0056] In another aspect the invention provides an improved method
of mounting an appliance operated by a power supply, which method
allows mounting/dismounting of the appliance without electrical
isolation from the supply said method comprising: providing a) a
mounting member having a first encapsulated transformer element and
suitable controls connectable to the power supply, said member
being suitable for fixing to a structure; and engageable with said
mounting member, b) a holder member suitable for holding or for
connecting thereto an appliance said member having a second
encapsulated transformer element and other suitable controls able
conduct power to the appliance; c) wherein engagement of the first
and second members is able i) to cause induction of current in the
second encapsulated transformer element enabling powering of an
appliance and ii) is able to cause a signal to be carried between
the controls and an appliance to control and/or monitor the
appliance; and wherein disengagement of the first and second
members results in no induction and no carriage of the signal; and
fixing said mounting member to a structure, connecting it to the
power supply, engaging the holder member and associated appliance
with the mounting member.
[0057] In another aspect the invention provides an improved method
of maintenance of lamp fittings or other appliances operated by a
power supply which method allows mounting/dismounting of the
fittings or other appliances without electrical isolation from the
supply said method comprising: provision of lamp fittings or other
appliances associated with couplings each coupling comprising a) a
mounting member having a first encapsulated transformer element and
suitable controls connectable to the power supply, said member
being suitable for fixing to a structure; and b) a holder member
engageable with said mounting member, wherein the holder member is
suitable for holding or for connecting thereto an appliance, said
holder member having other suitable controls and a second
encapsulated transformer element able conduct power to an
appliance; c) wherein engagement of the first and second members is
able i) to cause induction of current in the second encapsulated
transformer element enabling powering of an appliance and ii) is
able to cause a signal to be carried between the controls and an
appliance to control and/or monitor the appliance; and wherein
disengagement of the first and second members results in no
induction and no carriage of the signal the improvement comprising
that replacement of lamp fittings or other appliances can be
carried out under full power load by disengaging said the holder
member and replacing it with a fresh lamp fitting or other
appliance attached to a second holder member directly, or via a
cable.
[0058] Preferably the mounting member and the holder member when
engaged form a protective housing to help protect the outside of
the encapsulated elements from dust, dirt, moisture and the like.
Even more preferably the housing is weather resistant. This means
that the housing protects against the elements and is resistant to
ingress of moisture and/or dust, dirt and the like. Still more
preferably the housing is weather proof and can be hosed down with
high pressure water jets to facilitate cleaning of the lamp fitting
in situ.
[0059] Still more preferably the elements are engageable through
360.degree. of rotation about a longitudinal axis of the housing.
Even more preferably the members are of suitable dimensions such
that engagement is provided by one part of one member sliding over
another part of the other member. Preferably at least a part of one
of the members comprises a substantially cylindrical sleeve wherein
optionally the wall of the cylinder may be inclined or tapered.
Still more preferably a part of the holder member slides over a
part of the mounting member thus when slidingly engaged the
coupling is able to support the weight of the light fitting
enabling one-handed engagement and disengagement of the members.
Still more preferably the one of members is suitably threaded and
that members are fixed together by a complementary threaded annular
element such as a locking ring.
[0060] Even more preferably the holder member and light fitting
form an integrated unit suitable for coupling with the mounting
member. Still more preferably the lamp is an energy efficient lamp
such as LED. As such maintenance may be carried out in any weather
condition. The integrated fitting and coupling is fully sealed thus
negating the need for detailed inspections. The lamp comprises LEDs
making it maintenance free for at least 5 years. The sealed
coupling allows for light fitting replacement within 30 seconds
with no need for permits, gas tests, or any specialist equipment.
Due to having no exposed terminals at all and having no need to
disconnect any wiring the light fitting can be replaced by anyone.
There are no special skills or licenses required other than either
general or generic site or area inductions or training pertaining
to working in hazardous areas, once the coupling has been initially
connected to the junction box or similar appliance supplying the
power. All the above will reduce maintenance costs and time
considerably in most cases once the coupling is installed by
98%
[0061] Depending on the safety regulations in the country
concerned, maintenance of a light fitting at an industrial or
commercial site may require a hazard analysis to be carried out, a
permit to be issued for the work and a certificate of compliance to
be completed once the work has been carried out. Further most
safety standards require that the light fitting the electrically
isolated which in itself may present a difficulty. Many industrial
sites do not keep accurate records and circuit identification is
difficult. In addition for light fittings mounted at height it is
necessary to access them with a scaffold, cherry picker or platform
ladder. As some occupational health and safety standards require a
worker to maintain three points of contact with a secure base when
working from a stepladder or similar appliance, only one hand is
available to perform tasks such as removal of a light fitting. For
all these reasons, it is common on industrial and mine sites for
example for 20% of the light fittings to be out of service at any
one time.
[0062] In another aspect the present invention contemplates a
method of providing proximity activated control of luminescence in
at least one lamp comprising providing: a lamp fitting operated by
a power supply and mounted on a structure in a location, wherein
the lamp is associated with a coupling which allows
mounting/dismounting of the lamp without electrical isolation from
the supply, the coupling comprising a) a mounting member mounted on
a structure having a first encapsulated transformer element and
suitable controls connected to the power supply and a wireless
digital radio transceiver associated with said controls; b) a
holder member engageable with said mounting member, wherein the
holder member holds or has connected thereto a lamp, said holder
member having other suitable controls and a second encapsulated
transformer element able conduct power to the lamp; c) wherein
engagement of the first and second members causes i) induction of
current in the second encapsulated transformer element to power the
lamp; and ii) is able to cause a signal to be carried between the
controls and lamp to control and/or monitor the lamp; and wherein
disengagement of the first and second members results in no
induction and no carriage of the signal; and d) wherein
luminescence of the lamp is controlled by a remote controller via
the radio transceiver said remote controller being operational
within a predetermined distance from the coupling and/or
manually.
[0063] Manual operation is used in certain circumstances including
where it is desired to override the proximity control where for
example a person has not been issued with a transponder.
[0064] The location may be an industrial site, mining site, school
grounds or the like where lamp posts are fitted with lamps
associated with the coupling. Preferably the remote controller is
present on a key fob carried by a person or vehicle moving around
the site. Luminescence may be controlled by the lamps being turned
on, brightened or dimmed depending on where the light is
needed.
[0065] The present invention is partly predicated on the
recognition that employing a coupling which acts as a transformer
with encapsulated elements enables many issues with lighting
installation, control and maintenance to be addressed.
[0066] It has also been realized by the inventors that the coupling
of the present invention when fitted with a suitable communications
means may provide a network such as a communications SCADA
(Supervision Control and Data Acquisition) network.
[0067] Thus in another aspect the invention provides a method of
providing a distributed supervision control and data acquisition
network for controlling appliances remotely comprising providing:
lamp fittings or other appliances operated by a power supply and
mounted on power poles or other structures in a location and
wherein the appliances are associated with couplings which allow
mounting/dismounting of the appliances without electrical isolation
from the supply, each coupling comprising a) a mounting member
mounted on a power pole or other structure having a first
encapsulated transformer element and suitable controls connected to
the power supply; b) a holder member engageable with said mounting
member, wherein the holder member holds or has connected thereto
the appliance, said holder member having other suitable controls
and a second encapsulated transformer element able conduct power to
the appliance; c) where one of the members includes a wireless
digital radio transceiver able to receive signals from and transmit
signals to couplings attached to other poles or structures within
range and receive signals from and transmit signals to a control
station; d) wherein engagement of the first and second members
causes i) induction of current in the second encapsulated
transformer element to power the appliance; and ii) is able to
cause a signal to be carried between the controls and the appliance
to control and/or monitor the appliance; and wherein disengagement
of the first and second members results in no induction; and e)
wherein the coupling is able to receive signals from and transmit
signals to the control station allowing remote control of the
appliance in b) or another appliance associated with the
network.
[0068] The "location" may be an industrial site, a locality such as
a municipal council, a city, a road or a network of roads or
highways.
[0069] Preferably digital radio transceiver is incorporated in the
mounting member.
[0070] Preferably the control station is operated by the power
authority, municipal council or other body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0071] The invention will now be described with reference to the
following non limiting illustrative drawings.
[0072] FIG. 1 is a top view of the coupling the present invention
in use with a lamp fitting. The holder member and lamp fitting are
in the form of an integral unit.
[0073] FIG. 2 is a sectional view of the section A-A FIG. 1 showing
the male/female arrangement of the transformer.
[0074] FIG. 3 is a schematic representation of another embodiment
of the invention.
[0075] FIG. 4a is a schematic representation of the coupling of the
present invention.
[0076] FIG. 4b is a sectional partial view of the two parts of the
coupling when engaged.
[0077] FIG. 5 is a schematic representation of the primary side of
the coupling.
[0078] FIG. 6 is a circuit diagram of the mains rectifier and
auxiliary power supply of the primary side of the coupling.
[0079] FIG. 7 is a circuit diagram of the fly back converter of the
primary side of the coupling.
[0080] FIG. 8 is a circuit diagram of the central processing unit
(CPU) of the primary side of the coupling.
[0081] FIG. 9 is a circuit diagram of the secondary side of the
coupling.
[0082] FIG. 10 is a schematic representation of how the coupling of
the present invention may be used in a system for data acquisition
and control between locations.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS OF THE
INVENTION
[0083] The invention will now be described with reference to the
following non limiting drawings which relate to use of the
connector with an industrial light fitting similar to the
integrated light fitting disclosed in International Patent
Application No PCT/AU09/filed 31 Aug. 2009 claiming priority from
provisional patent application number 2009 9033765 filed on 20 Jul.
2009, which are herein incorporated by reference. It will be
understood however that the coupling of the present invention can
be used with other appliances operated by a non-battery power
supply such as power driven instrumentation appliances and
electrical motors, controls, valves, junction boxes and process
instrumentation as in a flow meter in a pipe rack and the like.
[0084] FIG. 1 shows the coupling 10 of the present invention in the
form of mounting member 12 and holder member in the form of an
integrated unit comprising lamp and lamp holder 14 which together
form protective housing 85.
[0085] FIG. 2 shows mounting member 12 having cylindrical sleeve 22
with open end 24 for receiving spigot 20 containing electrical
wiring (not shown) from the power supply. Spigot 20 is part of a
conventional mounting on a pole or the like for a lamp fitting. At
opposite end 28 of mounting member 12 there is provided first
encapsulated transformer element 130 in the form of a first winding
body and core (not shown) encapsulated within an appropriate
nonconductive resin or other appropriate material. Encapsulated
transformer element 130 is configured as a male component or
projection 135.
[0086] Light holder 14 comprises lamp fitting 46 having a plurality
of LED 84 and at one end cylindrical element 44. Second
encapsulated transformer element is provided by second winding body
150 which sheaths female component or recess 155. Recess 155 is
disposed partly within cylindrical element 44 and partly within the
body of the lamp fitting.
[0087] When holder member 14 and mounting member 12 are engaged
projection 135 mates with recess 155 allowing induction of current
in second encapsulated transformer element 150 thus enabling
powering of the lamp. The two members are fixed together by
screwing up locking nut 54. Upon disengagement and physical
separation of holder member 14 and mounting member 12 there is no
flow of current between the elements. This allows safe
disconnection of the holder member 14 from mounting member 12.
[0088] The coupling provides the contactless connection by using
the process of induction as provided by transformers. This is
achieved by having one half of the transformer encapsulated in a
body containing resin or other suitable material and the other half
of the transformer in a body containing similar resin or other
suitable material. The power is supplied permanently to the first
half. When the two halves are placed together and secured then the
coupling as an assembled unit acts as a transformer and allows
current to flow from the secondary side of the transformer windings
thus powering up and turning on the light. When the two halves of
the coupling are separated then each half discontinues to act as a
transformer thus causing the light to turn off and allowing it to
be removed and replaced if required. The light fitting itself
houses and array of low voltage LEDs making the fitting extremely
well suited for hazardous areas. The low voltage is achieved by
having the transformer made up of the coupling being designed and
wound so as to "step down" the voltage i.e. 240 volts is supplied
to the primary of permanently mounted side of the coupling and the
windings are such that when coupled with the second half of the
coupling the voltage is stepped down to a lower voltage e.g. 24
volts, via the transformer design allowing the use of low voltage
LEDS to create the illumination. The transformer elements of the
light are filled with epoxy resin or other suitable material so as
to allow all contact points be encapsulated and thus negating the
need for a detailed inspection at any stage of the fittings
life.
BEST MODE OF CARRYING OUT THE INVENTION
[0089] Similarly the second embodiment of the invention shown in
FIGS. 3 to 9 relates to a coupling 200 for driving an LED light
fitting from the mains supply without a galvanic connection. As in
the first embodiment, coupling 200 comprises mounting member 212
(primary side) and the holder member 214 (secondary side). Primary
side 212 is designed for permanent connection to a power source.
The energy to drive the secondary side is coupled magnetically
through a split transformer arranged in a face to face
configuration as distinct from the male/female arrangement in the
first embodiment. The secondary side contains LEDs and an internal
magnetically coupled power supply which is mechanically connected
to the primary side but galvanically isolated. This means that the
secondary side is removable during operation without the need to
disconnect power to the primary.
[0090] The face to face arrangement was found to be advantageous in
that it negates the need for precise engineering of components and
allows use of readily available parts such as ferrite cores for the
transformer.
[0091] In the second embodiment an optical communications path
allows digital data exchange between primary and secondary sides
either unidirectionally or half-duplex bidirectionally. This
communications path enables power feedback, identification,
dimming, blinking, colour changes, temperature as well as other
information or signals to be exchanged between primary and
secondary side.
[0092] As will be explained in the following description, the
electronics is designed so it can cope with a wide range of mains
voltages, detect the presence or absence of the secondary side and
compensate for varying secondary side loads and magnetic coupling
efficiencies. The combination of features (viz a CPU and a
communications path) allows the coupling to compensate for
imperfections in the cores, misalignments of the two halves and
power supply variations (such as allowing use with 110 and 240V
supplies).
[0093] The basic principle of the magnetic and optical coupling
between primary and secondary sides may be seen from FIGS. 4a and
b. The transformer comprises two standard ferrite pot core halves
234 and 264. The coils 237 and 267 comprise copper wire wound onto
half height custom machined plastic bobbins. Alternatively,
multilayer PCB coils may be used.
[0094] Translucent plastic end caps 240 and 280 which allow passage
of IR (infrared) cover the transformer halves thus providing
electrical safety clearance and sealing of the ends of the primary
and secondary sides. Optical feedback is via the secondary side LED
285 through light pipe 300, plastic caps 240 and 280 to the primary
side IR receiver module 245. PCBs 232 and 262 allow for mounting of
the electrical components and the transformer halves. Alternatively
PCBs 232 and 262 may be mounted on the end caps 240 and 280 with
standoffs that can be part of the end caps themselves. The exterior
profile of end caps 240 and 280 are complementary in shape.
Exterior of cap 280 has annular filleted projection which fits
within a complementary recess on cap 240. These features are
designed to self-centre the assembly. All internal voids are filled
with a suitable potting compound which would be known to a person
skilled in the art to hermetically seal the internal electronics
assembly.
[0095] The primary side consists of three major blocks: Power
Supply, CPU and Flyback Converter as shown in FIG. 5. These three
blocks enable energy to be taken from the mains connection and be
transferred to the first encapsulated transformer element 230 (see
FIG. 4) also referred to as the primary transformer. The other half
of the transformer is provided by second encapsulated transformer
element 250 (see FIG. 4) also referred to as the secondary
transformer.
[0096] The power supply to primary transformer 230 consists of two
main blocks as shown in FIG. 6: the mains rectifier, which provides
the unregulated main high voltage rail for the flyback converter,
and the auxiliary power supply, which provides a regulated low
voltage rail for the switchmode controller and CPU.
[0097] Referring to FIG. 6, the mains rectifier connection is via
the `LiveIn` and `NeutralIn` ports. The function of Fuse F1 is a
circuit overload protection feature (i.e. to prevent fire and limit
the follow-on current in the case of a catastrophic component
failure). MOV1 clamps mains induced transient spikes to a safe
level. C17, T2 and C18 form an electromagnetic compatibility (EMC)
filter to reduce entry of mains borne noise into the unit and also
prevent internally generated noise from being transferred to the
mains wiring. Diodes D6 to D9 perform a full wave rectification of
the mains AC voltage and charge up capacitors C14 and C15 to the
peak amplitude of the mains supply voltage (Vprim). C14 and C15 are
split into two parallel capacitors to minimise the electrical
series resistance and to allow the physical volume to be
distributed. C12, C13, C16 and C19 dampen spikes generated by the
nonlinearities of the diodes and assist in filtering mains
interference.
[0098] The Auxiliary power supply, also shown on FIG. 6 uses Vprim
and creates a regulated 12V rail (V12V0) with a dedicated low power
switchmode buck regulator integrated circuit, IC (U2).
[0099] The flyback converter shown on FIG. 7 uses a halfbridge
flyback topology to drive the primary transformer half from the
primary voltage rail (Vprim).
[0100] The operating principle is as follows: during the forward
cycle, MOSFETs Q1 and Q2 are both turned on simultaneously via the
highside/low side driver IC2, which in turn is driven by current
mode switchmode controller IC1. The current in the primary
transformer (L2) coil rises linearly, the rise time being dependent
on inductance of L2 and Vprim. This current causes a proportional
voltage drop in the current sense resistor Rs1. The dropped voltage
is fed back into the control IC1. When the current reaches a preset
value, both Q1 and Q2 are turned off simultaneously by IC1. During
this flyback cycle, the energy stored in the magnetic field of the
primary transformer is now either partially transferred to the
secondary side coil if the secondary side is present, or any energy
that is not transferred to the secondary side causes the voltage on
the primary coil to reverse and forward bias diodes D3 and D4
return the energy to the main supply rail capacitors C14 and C15. A
snubber network consisting of R5, R6, R10, R11, C6 and C9
suppresses spikes during the turn-off period and the reverse
recovery times of D3 and D4.
[0101] Since the energy that is stored in L2 in each cycle is
dependent only on the peak current and the inductance of primary
transformer L2, the converter represents a constant energy system,
irrespective of mains voltage (or Vprim) variations as long as the
switching frequency is constant. This allows the system to operate
on a wide range of voltages from 110 to 250V nominal. If Vprim
rises, the slope of the linear current rise in L2 during the
forward cycle will increase and the forward cycle will be
terminated earlier, thus maintaining constant energy for each
cycle. Current control will also compensate for any tolerances in
the inductance of L2, which will vary with the proximity of the
secondary side transformer half. Even though the energy levels per
cycle will change if the inductance of L2 changes, the peak current
for the switching MOSFETs is still well defined. This prevents
excessive stress on Q1 and Q2 in the absence of a secondary side
transformer half.
[0102] Whilst the current mode controlled diagonal half-bridge
topology is inherently self-regulating for varying supply rails,
mechanical variations in the gap between primary and secondary side
transformer halves will change both the leakage of the transformer
inductance and the inductance of the primary coil and therefore the
amount of energy that gets transferred with each cycle. Preferably
when the two sides are mated a gap of around 0.5 mm or less is
desirable however the coupling can function with a gap of about 1.5
mm but efficiency is compromised as EMR leaks away.
[0103] This issue may be addressed by two control inputs of the IC1
driven by the CPU to compensate for these variations and maintain
constant power to the secondary side. Specifically, there are two
different methods that can be used to control the duty cycle of the
IC1. One is via the voltage feedback pin 2 in which case Q4 is not
fitted and a rising control voltage on port Uctrl decreases the
pulse width modulation (PWM) ratio and hence reduces the power
level of the converter. The second method uses Q4 to reduce the
threshold internal current limit comparator of the IC2. In this
case R12 is not fitted which means that increasing Uctrl will
increase the current limit, whilst reducing Uctrl will decrease
it.
[0104] The above method is also employed by the circuitry around
Q3, which provides a hardware soft-start for the converter to
reduce stress during initial power-up of the primary side and to
give the CPU time to go through its reset cycle and start executing
code before the switchmode converter can overshoot and overdrive
the secondary side. The control voltage Uctrl is generated by the
CPU. IC2 has an internal 5V reference voltage regulator that is
used to power the CPU and the IR receiver.
[0105] The CPU shown in FIG. 8 is an 8 bit microcontroller with
internal oscillator (U1) that is powered off reference IC2 voltage
output. The code is loaded into the CPU in circuit via the
connector P1. U1 contains a hardware PWM unit that is brought out
to Pin5 and generates an analogue control voltage Uctrl via a
simple RC filter R4/C2. The digital signals from the IR receiver
module are fed into pin 3. Pin 2 can drive an optional status
indicator LED. The firmware for U1 is stored in on-board flash
memory. On-board EEPROM memory can be used to store serial numbers
and/or calibration data.
[0106] The basic function of the firmware is to check for the
presence of the secondary side on startup. In the simplest case
this is achieved by starting the converter for a short period of
time and waiting for a data signal on the IR receiver. If no data
is received within a timeout period, U1 can turn the converter off
for a preset period of time (typically a few seconds) to minimise
power consumption and emissions and then retry.
[0107] Alternative methods for detecting the presence of the
secondary side are using a reed switch connected to an input of U1
that detects the presence of a permanent magnet incorporated into
the secondary side, or the use of a reflex photo-coupler.
[0108] Referring to FIG. 9 the lamp holder or secondary side uses
the other half of the split transformer (T1) to receive energy from
the primary side. Feedback to the primary is sent via an IR LED
that sends a 38 kHz modulated infra-red signal through an optical
light-pipe or light path 300 (see FIG. 4a and b) to receiver module
of the primary 245. Feedback includes information about temperature
in the light fitting from a temperature probe.
[0109] The energy that is induced into the two windings of the
split transformer half T1 during the flyback period of the primary
is used to drive a series string of white LEDs from the main
winding and to provide an auxiliary supply voltage rail to power
the control electronics. During the forward period of the primary
side both D6 and D9 are reverse biased and no energy is
transferred. As the voltage on the coils of T1 reverses during the
flyback period of the primary side, both D6 and D9 become forward
biased and charge up C3 and C6 respectively.
[0110] The turns ratio is chosen so that the appropriate voltages
are obtained for the respective two rails Vin and Vaux. Vin is
determined by the number of LEDs in the series string, the type of
LEDs and the series/parallel configuration. Typical values for Vin
are 30 to 60V. Vaux has to be higher than the minimum input voltage
of the 5V linear voltage regulator chip IC1, typically 7 to 10V.
The turns ratio may be easily determined by a person skilled in the
art.
[0111] The string of visible LEDs is driven by a constant current
source formed by Q4 and Q5. The voltage drop on current sense
resistor Rs1 is proportional to the LED current and limited to a
maximum equal to the Base-Emitter threshold voltage of Q5
(typically 500 mV). Operational Amplifier U2 amplifies voltage by a
factor of .about.10 and feeds it to an analogue to digital (A/D)
converter input of microcontroller U1 (Pin 3).
[0112] A second A/D input of U1 (Pin 7) is connected to the drain
voltage of Q4 and can measure the voltage headroom that is
available for the constant current source. PWM output Pin 5 is used
to generate the 38 kHz carrier signal for the IR LED, a general
purpose input/output (I/O) pin (Pin 2) is used to modulate this
carrier. The IR feedback LED is driven by a constant current source
formed by Q1 and Q3 and the carrier modulator Q2. In circuit serial
programming of the microcontroller U1 is facilitated by connector
P2. To keep the LED string current and hence the lamp brightness
constant irrespective of split transformer coupling efficiencies,
core half separation distances and mains voltage variations, U1
measures the LED current by measuring the voltage drop on Rs1,
digitally encoding the current value and sending the signal to the
Primary's CPU by modulating the 38 kHz signal with the A/D data.
The CPU of the primary side adjusts its switchmode converter's duty
cycle through a software proportional-integral-derivative (PID)
controller until the nominal secondary side LED current is
achieved.
[0113] There are two regulation modes that can be selected in
software. In the first mode, the current is regulated to just below
the LED Current Source's constant current cut-in value. This is the
most energy efficient mode as there is minimal voltage drop across
Q4. The main purpose of the constant current source around Q4 is to
limit the maximum LED string current to a safe value in the case of
a current control loop overshoot, which could otherwise damage the
LEDs. Whilst being efficient, the disadvantage of this mode is that
short term variations cannot easily be compensated for since the
time delays involved in A/D conversion, data transmission and PWM
integration mean that the feedback loop has to be relatively slow
to be stable. This can lead to visible flicker and brightness
variations during the slow control loop's adjustment phase.
[0114] In the second mode the current is governed solely by the LED
current source Q4/Q5. To trade off efficiency versus regulation
headroom, the Q4's drain voltage is measured by U1 and kept
constant through feedback to the CPU of the primary side.
Maintaining a higher voltage will enable larger variations in Vin
before Q4 loses regulation, at the expense of higher power
dissipation in Q4. This headroom/dissipation tradeoff can be
changed dynamically in software, based on a history of measurements
that takes the average variations in the current working
environment into account.
EXAMPLE 1
Use of Coupling for Data Transmission and Acquisition
[0115] The coupling of the present invention is used to provide a
network suitable for data transmission and control relating to
street lighting, power metering and other appliances. In this
embodiment the coupling incorporates a device providing high level
communication protocols using small, wireless, low power digital
radio transmitter/receivers such as a zigbee.TM. chip or router.
Preferably the device is incorporated into the mounting member and
receives signals/information from the controls such as when lamp
has blown or is not operating properly.
[0116] In the system shown in FIG. 10 faulty street lamp in town A
fitted with the coupling is able to transmit a signal via a series
of similarly fitted street lamps back to the power authority. The
signal is received and a maintenance person dispatched to replace
the faulty lamp.
[0117] Similarly a power meter on a residence in town B may be read
by the power authority issuing a signal asking the meter for its
reading or by the meter transmitting readings at predetermined
intervals (say every billing period). Thus the power meter may
transmit data concerning power consumption or requirements to the
power authority and/or may receive control signals from the power
authority to reduce consumption in periods of high demand. Power
meters or submeters such as those produced by Saturn South.TM. may
be used in this system.
[0118] Optionally each of the appliances used with the coupling has
its own internet protocol (IP) address to facilitate further
control of the appliance.
[0119] In the system contemplated a series of street lamps with the
light fittings of the present invention provides a distributed
secure control network which avoids the need for telephone cables
to transmit data. In a sense the invention provides for a de facto
network. The network has the ability to act as an "intelligent
swarm". Should one or more of the light poles be damaged (by a
storm or a vehicle accident) the remaining nearby poles fitted with
the coupling incorporating digital radio transmitter/receivers are
able to locate each other and compensate for the damaged poles.
[0120] It can be seen from the above that the coupling of the
invention has many uses such as remote reading of power meters,
real time monitoring of power distribution system performance,
transponder tracking, reporting faults with street lights or other
equipment. Control of remote loads such as equipment in a person's
home by a power authority is also possible where household
equipment associated with the coupling has its own IP address and
can be switched on or off via a router and broadband connection.
This may enable the supply of power at low demand times.
EXAMPLE 2
Use of Coupling for Controlling Lighting at Industrial Sites
[0121] The invention allows for remote control of lighting in large
areas such as industrial sites where it may be desirable to save
energy. At night or other times the lights may be run at half
brightness and only powered up to full brightness when needed. This
may be achieved by lights used with the coupling having a zigbee
chip or similar incorporated into the controls of the primary side
and activated by a controller on a key fob or the like carried by a
worker. As the worker moves around the site the lights are brought
up to full brightness and are dimmed after a predetermined time
once the worker has moved away. In this embodiment the controller
in the key fob acts as a coordinator of a zigbee or similar
network. Thus the invention also provides for a method of proximity
controlled dimming/luminescence of a light or lighting system.
[0122] Throughout this specification and the claims that follow,
unless the context requires otherwise the words "comprise",
"comprises", "comprising" will be understood to mean the inclusion
of the stated integer, step or group of integers or steps but not
the exclusion of any of other integer, step or group of integers or
steps.
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